Electric train-lighting system.



J. F. McELROY ELECTRIC TRAIN LIGHTING SYSTEM.

APPLICATION FILED DEC. 15, 1905. RENEWED NOV. 16,1914.

Patented July 6, 1915.

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ELECTRIC TRAIN LIGHTING SYSTEM.

APPLICATION FILED DEC. 15. 1905. RENEWED NOV. 16.1914.

1, 145,328. Patented July 6, 1915.

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rrnn STATES PATEN OFFICE- J'AMES F. MOELROY, OF ALBANY, NEW YORK,ASSIGNOR, BY MESNE ASSIGNMENTS, TO CENTRAL TRUST COMPANY OF NEW YORK, ACORPORATION OF NEW YORK,

TRUSTEE.

ELECTRIC TRAIN-LIGHTING- SYSTEM.

Specification of Letters Patent.

Patented July 6, 1915 Application filed December 15, 1905, Serial No.291,824. Renewed November 16, 1914. Serial No. 872,499;

To all whom it may concern Be it known that I, JAMES F. MoELRoY, acitizen of the United States, residing at Albany, in the county ofAlbany and State of New York, have invented certain new and useful Imprvements in Electric Train- Lighting Systems, of which the followingspecification and accompanying drawings illustrate the invention in aform'which I now regard as the best out of the various forms in which itmay be embodied.

This invention relates to the electric lighting of trains by axle-drivengenerators and involves, in the first place, an arrangement whereby froma single dynamo there may be derived a widely variable potential for thestorage-battery and an unchangeable potential for the lamps. In thesecond place, it involves an arrangement for lighting trains, asdistinguished from separate and independent cars.

As regards the first part of the 1nvent1on, I would say that I haveheretofore employed a system in which a certain dynamo potential hasbeen applied to the lamps and storage battery in multiple, being appliedto the latter directly and to the former indirectly through a potentialreducing resistance. The potential thus applied to both lamps andbattery has been substantially a constant potential, but modified fromtime to t me during such periods as the battery s being charged to meetthe changeable requirements of the battery, such modification beingwithin the limits of permissible potential varlation at the lamps,which, it will be noted, received the same potential as the batteryminus that subtracted by the lamp resistance. This modification ofpotential was provided for by means of a modifier-coil in series withthe storage battery and arranged to supplement, and so modify, theeffect of the potential coil, which constantly measures the dynamopotential and, in the event of any increase or decrease thereof above orbelow the given standard, sets in action potential adjusting agenciesMuch Will correct the ncreasing or decreasing tendency and maintain thepotential at the aforesa1d standard. The effect of the modifier coil isto change, according to the value of the current flowing through thecoil into the battery, the standard potential which the apparatus tendsto maintain during the charging operation.

Such a system is an effective one, but in some cases, I find it notsufficiently flexible to meet extreme requirements, and therefore I havedevised the present arrangement, wherein the modified potential isapplied to the storage battery only, this being secured by changing thepoint at which the potential-coil will come into action, and interposingin the lamp circuit an automatically adjustable resistance which\villcancel out the modifying effect of the said modifier coil, so faras concerns the lamps. This makes the lamps independent of thepotential-changes imposed on the storage battery to suit the storagebattery conditions at different stages of the battery-chargingoperation; and, conversely,- it makes the said potential changesindependent of the lamps. I am therefore enabled to utilize a widerrange of potential-variations in charging the battery such as would notbe available if the lamps were exposed to the same range of changes.Moreover, in my previous system aforesaid I arranged to close the mainswitch, which connects the dynamo to the circuit, when the dynamo speedis suflicient to give the dynamo a potential substantially equal to thelamp-potential, and I thereafter caused the regulator to maintain ahigher potential suitable for charging the battery by automaticallyincreasing the tension on the retracting spring of the regulator magnet,which also controlled the said main switch. In my present arrangement Igive the retracting spring of the regulator magnot a permanentadjustment, and, in opposition to the spring, I so construct the magnetthat it will exert a substantially constant pull against the springduring the entire range of potential-variation. In connection therewithI provide a separate magnet for operating the said main switch, thismagnet being energized by shunt and series windings according to a wellknown principle, and set to act at a potential not higher than thelowest battery-charging potential.

As regards the second part of my invention, to-wit, lighting of a train,as distin-: guished from individual cars, the arrangement 'iust referredto is particularly fitted for. this purpose. In addition, I providedevices, usable with the aforesaid car arrangement, or with any othersuitable substitute therefor, which aim to meet the practical conditionsfound in the train situa-' tion. I provide each "car of the train withan individual apparatus, such for instance as I have referred to above,but each dynamo is made of a capacity adequate to supply the needs ofone or more cars in addition to those of its own car. All the dynamos ofthe train are then connected in multiple to train- .Wires extendingthrough the train and serving as feeders to transmit the surplus energyfrom one or more dynamos of the train to other cars where a deficiencyexists. By

' this means a train can be made up of cars having their batteries indifierent stages of exhaustion and their respective machines a littledifferently adjusted, or in a more or less perfect working conditionand, by the arrangement just mentioned, the deficiencies of certain carswill be made up by the surplus from other cars. Moreover I providebetween each dynamo and the re ceiving apparatus on any foreign car acertain resistance which will tend to limit the amount of a current itwill deliver to the foreign car as compared with that delivered to itsown car, so that only the surplus which can be spared by its own lampswill be sent to assist the other cars. Preferably this resistance isinserted between the battery mains of each car and the train-line andthe train-line is made of very low resistance, so that the surplus canbe delivered to any car of a long train that may require assistance.

In the accompanying drawings-Figure 1 illustrates diagrammatically thepreferred circuit arrangement for a single car. Fig. 2 illustrates aseries of car circuits showing the relation of the difierent cars of thetrain to each other.

Referring to the diagrams of the drawings, A represents an axle-drivendynamo connected to the car-mains a and of, which are in turn connectedto the respective train lines 1 and 2 with an intervening resistance E.The main switch is indicated at I) and the usual shunt and series coilsd and d for operating it. From the car-main a, one branch of the currentflows from the point 15 through the storage battery C, and thencethrough the modifier coil 13 (to be described later) to the main a atthe point 16. The other branch of the current flows from the point 15through the lamp-resistance R, and thence from the contact 7" of theresistance to the lamps L and to the main a To maintain independentpotentials at the battery and the lamps, the battery-potential changingaccording to the battery conditions and the lamp-potential remainingconstant, I employ two shunt or potential magnets, one for the battery,and the other for the lamps. The former magnet is supplemented by theaforesaid modifying coil in series with the battery, and the latter actsalone Without such modifier. Each of these magnets I use to control amotor which operates a regulating resistance, the regulating resistancecontrolled by the batterymagnet being contained in the field-magnetcircuit of the dynamo A, and that con trolled by the lamp magnet beingcontained in the lamp circuit in series with the lamps. 2 is the batterymagnet, its shunt coil being connected to the main a at the point 17 andto the main a at the point 18.

B is the lamp magnet connected on one side to a at the point 19 and onthe other side to a at the point 20.

The shunt coil of the battery-magnetis supplemented by the modifyingcoil B above referred to in series with the battery. If the battery isexhausted and its counter pressure thereby reduced, a large current willtend to flow into it and through the modifying coil. This will give thebattery magnet an initial strength, so that its total strength (i. e.the strength required to hold its core in the neutral position againstthe force of its retracting spring S) may be secured by a lesser currentin the shunt coil (corresponding to a lesser potential on the car-mains)than would be the case, if this initial strength were less or absentaltogether, which would be the case if the storage battery were nearlyor wholly charged and its counter pressure nearly or fully equal to thecharging pressure.

M is the motor controlled by the battery magnet B, and it has twodistinct field magnet coils 8 and 9 which are oppositely Wound, so thatthe motor will rotate in one direction when current is admitted to itthrough fieldmagnet coil 8, and in the other direction When current isadmitted to it through field-magnet coil 9. The motor is in a shuntcircuit between mains a and a Starting from main a at the point 18, thiscircuit goes to the point 21 and thence to a contact 10 on the tip ofangle lever F, operated by magnet B Vhen contact 10 touches a contact 6,just above it (when magnet B becomes too strongly energized and draws inits core Z2) then the motor circuit will be closed through field-magnetcoil 9. When, on the contrary, contact 10 touches the lower contact 7,the motor circuit will be closed through its fieldmagnet coil 8.Normallythat is when the battery voltage is satisfactory to the magnet Bits core I) will hold the contact 10 out of engagement with both of thecontacts 6 and 7 and it is this satisfied condition of the magnet Bwhich is produced by a greater or less voltage of the main dynamoaccording to the less or greater current in the battery-branch coil ofthe magnet, and the less or greater value of the initial power i1n--parted to the magnet thereby. Therefore when the battery is exhaustedand a large current tends to flow into it, the magnet B will besatisfied by, and maintain a lower dynamo voltage; and, on the otherhand, when the battery is fully charged and little or no current tendsto flow into it, a higher dynamo voltage will be required and maintainedto keep magnet 13 in satisfied condition. Any departure from thissatisfied condition caused by an increase or decrease of dynamo voltage,such for instance as would result from speed changes of the train,willbring contact 10 into engagement with either contact 6 or contact?and thereby set the motor to work to change, the amount of resistance Rin. the field-magnet circuit of the dynamo, and thereby correct thedeparture by increasing or decreasing the power and voltage of thedynamo, until the magnet B is again satisfied and stops the motor bybreaking its circuit at the contact 10. When the train stops, the effortof the apparatus to maintain the falling voltage will bring theresistance contact 1, of resistance B, into the position shown in Fig.1, with all of the resistance removed from the field magnet circuit.That circuit is a shunt across from main a to main a starting at thepoint 2% and going thence to contact 1, and through more or less or noneof the re sistance R, to the dynamo field magnet f, whence it goes tomain a at the point 18. As the apparatus arrives at this off position ofFig. 1 a projection Q, on the rotating part which is driven by the motorM through screw shaft 0, strikes and opens a circuit breaker g in themotor circuit through field coil 8 (which has been operating to bringthe parts to this off position) and so leaves that circuit open so longas the train is at rest and prevents a waste of battery current whichwould result if the circuit were left closed during that period, Whenthe train starts again, it is necessarily the other motor circuitthrough field magnet 9 which first comes into action (to check the riseof dynamo voltage) and when this occurs it moves stop Q away fromcircuitbreaker q and allows it to close. The motor M has a governor LT,which acts to prevent racing of the apparatus by breaking the motorcircuit, if its speed becomes too great.

The purpose of the apparatus thus far described is to maintain thedynamo voltage at a point which is determined solely by the batteryrequirement, and since this involves, in certain situations, adynamo-voltage having a range of variation greater than is desirable atthe lamps, T have provided the resistance R which will be automaticallyvaried in amount in accordance with the potential-variations on thebattery. The resistance R is operated, like resistance R, by means of amotor, M which, like the motor M, has two oppositely wound field magnets28 and 29, whose circuits are controlled by a contact 100, operated bythe core of magnet B and playing between upper and lower contacts 60 andwhich form the respective terminals of the field magnets 28 and 29. Thecircuit of field magnet 28 is provided with a circuitbreaker g operatedby a projection Q, corresponding to and for the same purpose as thecircuit-breaker g operated by the projection Q. This projection Q, movesthe contact member 9 to open the circuit of the field winding 28 whenthe arm T has returned to initial position to cut outall the resistancefrom the lamp circuit. WVhen the regulator operates to insert resistancein the lamp circuit, the field winding 29 is energized and operates themotor in a direction to cut in resistance, thereby closingthe circuittothe field winding 28. vVhen all the available resistance R has beencut into the lamp circuit, the projection Q has moved around andoperates thepother contact member 9 thereby stopping the motor. Themaximum resistance remains in the lamp circuit until the conditionswarrant a reduction in said resistance, whereupon the other. fieldwinding 28 becomes energized and reverses the motor, thereby closing thecircuit to the field Winding 29.. The magnet B shunting the lamps L willmeasure the potential applied to the lamps, and, as that potential tendsto increase or decrease by reason of an increase or decrease in thepotential applied to the battery, it willclose the circuit of motor Mand cause it to rotate in one direction or the other to introduce alarger portion of the resistance R in series with the lamps L when thereis a tendency to potential increase and, conversely, introduce a smallerportion thereof in series with the lamps when there is a tendency to apotential decrease. By this means the potential of the lamps L will bemaintained constant in spite of wide variation in the potential appliedto the battery. The motor M is also provided with a contrifugal governorcorresponding to the governor N of the motor M.

In Fig. 2 I have indicated diagrammatically a series of car-circuits,like that included in Fi 1, applied to the respective cars of a four-cartrain. Between the trainlines 1 and 2 and each of the respective carcircuits is interposed a resistance E. It will be understood that thedynamo of each train has a capacity to supply more current than isrequired by the demands of its own car. For illustration it may beassumed that on the first car, beginning at the left, the

battery conditionsvare, at some given time,

such as to require a dynamo potential of 80 volts, while on the threeremaining cars the dynamo voltage is respectively 75, 70 and 63 voltsand, moreover, that the 80 volt car is capable of supplying current forits own needs and sparing 25 amperes for the needs of other cars. Thenit follows by on the train-line a potential of 72 volts at 4 all points,and, while the first car delivers to the train-line a current of 25amperes and the second car a current of 9-8/8 amperes,

there will flow from the train-line to the third car a current of 6-1/4amperes, and to the fourth car a current of 28-1/8 amperes. Thisrepresents a practical but extreme condition, the maximum and minimumvoltages being in ordinary cases within narrower limit. In all cases,however, it is desirable to employ the resistance E, which will be of avalue dependent upon the capacity of the several dynamos and theapproximately mean voltage to be maintained on the train-line. Theresistances E will act to protect the supply of any individual car bylimiting the amount of surplus current which it can deliver to theothers, and at the same time it will protect the regulator on each carin its duty of iving to its own battery the appropriate potential as maybe determined by its individual regulator, instead of an unduly highpressure such as might be otherwise received from a car whose battery iscompletely charged and whose voltage therefor is at a maximum, or atleast higher value.

lVhat I claim as new and desire to secure by Letters Patent is:

1. In a train lighting system, the combination of local conductors a aon each car, lamps and a storage-battery on each car connected to thesaid local conductors in multiple, a dynamo on each car also connectedwith these conductors, means for adjusting the voltage of each dynamoaccording to the conditions of the local battery on the same car, and avoltage-reducing train line connecting thedynamo and battery terminalson one car of the dynamo and battery terminals on one or more adjacentcars. l

2. The combination with a railway car, of an axle-driven dynamo having acapacity greater than is required by the car, a trainline, a resistancebetween said train-line and the dynamo, a local circuit connected to thedynamo between the dynamo and said r resistance and lamps connected tosaid local circuit through a resistance.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses, the 13th day of December, 1905.

JAMES F. MOELROY.

Witnesses:

BEULAH CABLE, ERNEST D. JANsnN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

